1. Field of the Invention
The present invention relates to expanding mission capabilities and payload architecture for UAV system wing designs though the means of an open-architecture payload bay. More specifically, the present invention relates to wing designs with integrated aerodynamic payload integration systems for unmanned aerial vehicles (UAVs).
2. Background of the Invention
Unmanned aerial vehicles (UAVs) are unpiloted aircraft which may be controlled remotely or based upon a pre-programmed flight plan. UAVs have become an increasingly important tool for law enforcement, military, and security personnel to travel and gather information from otherwise hostile territory. Types of UAVs are used for reconnaissance as well as attack missions. Though conventional UAVs have been highly successful in gathering video or footage of the terrain and personnel within hostile territory, the gathering of other types of data has been a more difficult undertaking. Part of the reason for such difficulty is that UAVs are generally very light, some on the order of 5-10 pounds, and the installation of heavy equipment or other bulky payloads completely distorts the flying and maneuvering abilities of such aerial vehicles.
This disclosure concentrates on small, hand-deployed UAV systems that are assembled in “kit” form with the wing sections being their own sub-components or made of multiple sub-components. One type of small UAV, the RQ-11 RAVEN, is a modularly assembled remote controlled tactical UAV used by the military. The RAVEN is approximately 5 pounds with a battery, approximately 4.5 pounds without. The RAVEN came into common service in the military community, mainly the army, navy, and marines, as a small tactical UAV. The RAVEN has a basic capability of being able to fly for roughly an hour under the control of a local user. Alternatively, the RAVEN may fly completely autonomous missions using GPS waypoint navigation. The sensor capabilities of the RAVEN include electrical-optical or infrared (EO/IR) full motion video cameras. Infrared capability allows for night flying of the RAVEN.
Currently, most small UAVs are produced with optical surveillance capability and have little to no add-on or enhancement features to increase the base mission capability. They are typically designed to be man packable, reusable, and have a very small supply footprint, such that a unit can hand launch it, fly it around, scout ahead, and then bring it back.
More recently, the intelligence community has begun to see small UAVs as a convenient platform to try and deploy small sensors and serve as test bed for small enhancement features. A current example of how the military currently accomplishes this is through crude attachment means (i.e., duct taping payloads to the top of the wing). An alternative was actually carving into the wing itself with a DREMEL tool then gluing components into the wing. Either way requires a very manual process, and the end result is not rugged. Furthermore, an inordinate amount of man hours are spent guessing as items are placed wherever they can fit on the center wing section with no protection against failures, center of gravity effects, or drag. Not surprisingly, these types of payload attachments have caused many problems. For example, with the duct-taped payload, the RAVEN only reliably flies about 45 minutes or around three-quarters of its normal flight time due to degraded aerodynamics (increased drag), and increased weight. This may be even shorter, depending on how heavy the attached payload is. Thus, there have been different configurations attempted, but each has resulted in a significant drop in the flight time.
From a weight perspective, a payload affects the flight systems themselves. Some of the lost flight time comes from a heavier payload forcing the motor to work harder to get the RAVEN up to altitude and constantly re-climbing, because every plane has a glide ratio. Also, because the center of balance of the RAVEN changes along with the drag, the RAVEN with the payload could porpoise, affecting the ability to keep a camera focal point on target.
Furthermore, the takeoff of the RAVEN is significantly affected. While testing did not produce stall outs, many of the takeoffs do not perform in a normally observed manner, presumably all due to the weight increase. This is a significant problem in some of the overseas areas in which the RAVEN is used because of high temperatures. In these high temperatures, the air is less dense, and the airfoil generates less lift. The additional drag and extra weight of the payload on the RAVEN without having some kind of lift characteristics due to the packaging causes improper or failed takeoffs. In the worst cases, the platform never makes it off the ground. Users are forced to try to find spots with an elevation, for instance, by climbing up a tower to launch it from, just to guarantee that the RAVEN gets enough speed that it can generate the lift it needs to take off. This is far different than the normal takeoff by throwing the RAVEN from the ground.
A battery, camera systems, and communications downlinks are all packed into the body of a UAV such as the RAVEN. The wing of a UAV, however, is composed of an ultra-light weight foam material. Though few components are small enough to be completely embedded in the wing, a slight redesign to make a cavity within the wing is not as costly in terms of efficacy as long as the wing remains aerodynamic.
Thus, what is needed in the art is a system and method to carry payloads or other equipment on UAVs already in use. Such systems and methods should be easy to understand and implement, and adaptable to existing UAVs such that very little re-design of the conventional UAV is needed. An integrated payload attachment including elements necessary for the electromechanical functioning of the payload is ideal.